Wayne, I make no apologies for the tone of my posts, often the reader inserts their own perception of tone. The big problem for forums like this. Mind you, protecting your investment and family is no time for politically correct stuff either.
As for the protecting what I learned, there could be an argument that if I had paid for (and attending Ada from here costs me way more than you) an education, why should you and others get it for free. That sounds fair right? In fact I actually do think that is a fair call, but given the knowledge is out there anyway, and George, John and Walter share it all openly anyway, its no big deal.
The Big deal is in one or two posts on VAF I can not do anything like the educating they do in a weekend. Simple as that.
The thing is, all I can do is show you a glimpse of what you do not know already and open your eyes / mind to the world of more training and understanding. Right now neither you nor I can be sure if you REALLY understand something I posted. In a open classroom with real engines on a Dyno.....you will understand.
That is the reason I push the APS courses so hard....I know first hand....I learned heaps through my own self study and my own experimenting, with an engineers mind and some good gear, but until I understood stuff from grass roots, the rest was all just stuff I read about. I reckon I only know about as much as george Braly has forgotten, so I am not the end of the story, just a beginning.
Now back to the quizz...........understand this, I am going to be harsh on you, OK.....but for good reason, you might see why at the end.
First, remember to fly the plane. My wife will have the nrst airport page up on the 496 and select "direct to" our chosen landing site. I will select gps2 on my grt and turn towards it. At the same time thinking of the possibilities...
1. Detonation- reduce power and enrich mixture, land as soon as possible.
I have my cht alarm set at 435F. I will try to avoid flying over mountains at night, plan night flights with a full moon, always have 2 hrs+ fuel on board and fly as high as possible.
Let me tear this apart into bite size pieces, remembering the scenario I gave you. No applying any of your own twists to it
1. Hitting the NRST and going there is great, takes about 5 seconds to do all that stuff out of the 60 you had. Remember you are over the middle of the Rockies and no airports for a really long way.
2. Detonation: WRONG DIAGNOSIS, I said falling EGT and rising CHT (and fast just like detonation)
Reducing power is not possible or very limited, given where you are and the Lowest Safe, you need as much power as you can get, and 5 out of six are working well.
Land as soon as possible: Well that is a no brainer when you hear the answer and I would say you are 100% right, but you only have 55 seconds left before you are engineless.....and well you know it might be 30 minutes to the nearest airport.
Enrich Mixture: yeah but how much? at 14000 feet how much? Do you do just a little and see what happens, or do you go full rich and put up with an engine that under performs and coughs a bit due way too much fuel?
I have my cht alarm set at 435F. I will try to avoid flying over mountains at night, plan night flights with a full moon, always have 2 hrs+ fuel on board and fly as high as possible.
Lets deal with this one for a bit, If you had not noticed the EGT drop and CHT rising, and you were looking at the moon and stars, then your alarm goes off at 435, by the time you actually look closer at it its racing through 450, and by the time you do the NRST......you have a failed engine
Wayne and anyone else reading this, please, PLEASE set your alarms at 400 max and if they have a yellow at 380. There is no down side to doing this and only upsides for doing, it buys you time, so no arguments whatsoever please.
I agree, avoid the Rockies at night and fly as high as you can etc etc etc, but that was not the mind flight was it
But I am glad we all think that way. There are times when I am over far more remote country at night down here than you guys can imagine, so its a big deal.
So back to the answer: I think you saved yourselves, but I am not sure. You had 60 seconds before it all went pear shaped, and an outlanding up there would most certainly not end well.
Had you said GO FULL RICH.........I would say yes you were saved. Pulling back power might help, but you could not afford that, or not much anyway. Drifting down is not much better when its a rocky cliff.
So what causes a falling EGT and a rising EGT? A broken ceramic on a spark plug and a chunk falling off, Pre-ignition sets in. That spark plug is now a glow plug and the only thing that will stop it is an overly rich mixture that the glow plug cant get the charge away under "preignition terms", yes it may run a bit rough from overly rich but it will run, and the damage done will hopefully be not to sever to last another 30 minutes.
Of course on the lean side of peak you could make the mixture so lean it stops too.......hehehheheh but so will all the other cylinders
And that is only an option in a Baron or similar twin.
False diagnosis is just as bad as no idea. Can you be correct all the time, probably not, but the education you get can help. If nothing else it can save you money over time.
By the way, I was running some engine health classes on the weekend at a major national fly in, mainly about Leak Downs, Borescoping and EMS's and education, so I asked the audience at the beginning about that mind story, and came back to it later, and gave them a minute to tell me what to do before they killed me
.......one bloke saved my bacon. He said full rich, and only because he had this happen to him. He had a single probe CHT/EGT and was just lucky the preignition event happened on that cylinder. He had no idea what was wrong but just went full rich. He made it to a sandy airstrip on an island close by. One cylinder was toast, but it survived long enough. He only just caught a glimpse, it took not long at all. He had a broken ceramic.
I was amazed I had someone in the class that had this event, salvaged it correctly, not knowing why or how he did, and did not end up being shark food. He is now a big believer in engine monitors!
So again I say.........we do not know what we do not know, me included. There are many more things like this an EMS can tell you, even just maintenance things, so I reckon a small price to pay, and a likely payback.
Cheers!
DB